import java.io.*;import java.util.Scanner;public class kaisa{    public static void main(String[] args){        System.out.print("请输入密钥:");        Scanner s=new Scanner(System.in);        int a=s.nextInt();        C(a);    }    public static void C(int n){        try{            char b[];               BufferedReader br2=new BufferedReader(new InputStreamReader(System.in));               System.out.println("请输入一段明文:");               String str2=br2.readLine();               b=str2.toCharArray();               System.out.println("密文为:");               int k=n;               for(int i=0;i<str2.length();i++){                   char ch=(char)((b[i]-'a'+k)%26+'a');                   System.out.print(ch);               }               System.out.println("密匙k="+k);        }catch(IOException e){            System.out.println(e.getMessage());        }    }}